WowAce

Officially the original source of knowledge of where things are in Draenor during Warlords, in HandyNotes

A skinning engine for button-based add-ons.

Tracks Raid/Instance/World Boss lockouts for all your characters, daily/weekly quests, currencies, trade cooldowns, and more!

Ackis Recipe List is an addon which will scan your trade skills and provide information on how to obtain recipes. It works fo...

An intuitive keybindings library.

Replacement for ActionButton_Show/HideOverlayGlow APIs

Creates and manages secure Action Buttons

Library to check whether an item is equipable / appropriate for a given class

Another HUD addon

Modular casting bar.

Uses various methods to scan your surroundings for rare or specified NPCs.

Modular damage meter.

Estimated range display. Type /rangedisplay for config

Allows you to view all items from all your characters on the same account, when-ever and where-ever you want.

Shows the possible loot from the bosses

"Debug" code free since '93!

Postal: Enhanced Mailbox support

Core module for Loot and Looting-related UI improvements

In-game theorycraft. Calculates actual damage/healing based on gear, talents and buffs.

A library allowing for easy creation of graphs